This invention relates to a method for preventing unauthorized access to the interior of a fluid container and to a valve which may be used in the method.
Valves are mechanical devices used to control the flow of a gas or liquid. Control is exerted by means of a movable element mounted on a valve seat, that opens, shuts or partially obstructs an opening in a passageway. Numerous types of valves exist, including gate, globe, needle, plug and butterfly valves. A check (or non-return) valve is a valve which automatically limits flow to a single direction. Check valves are very useful when flow is desired in one direction, but not in the opposite direction. Generally, the movable element is displaced by the fluid flow so as to allow flow in the desired direction. If, however, the flow direction reverses, the element is compressed by the flow against a valve seat thereby obstructing the fluid flow. Thus, the flow control of the valve is self-acting, being controlled by the fluid flow.
Various types of pressurized fluids, both liquids and gases, are often stored in reusable containers. The containers are generally sold, leased or given by the fluid manufacturer or marketer to retailers or consumers with the understanding that the manufacturer is the sole source of the contents of the container. This understanding may be expressed as a clause in an agreement between the supplier and the customer, or may be as a result of local legal requirements and/or safety regulations. The manufacturer of the fluid therefore has an interest in ensuring that an unauthorized party is unable to tamper with the contents of the container, e.g. to introduce another fluid into the container.
One example of the above relates to LPG (cooking gas) containers or cylinders. A gas supply company which sells or leases a gas container to a consumer will usually also contract to refill the container when it is empty, thus allowing the company to earn a profit. The company is therefore interested in preventing competitors from refilling its gas containers with the competitor""s gas. Another example is reusable pressurized soft drink containers, where the consumer wants to be certain that the liquid in the container is the original liquid. A further example relates to reusable beer kegs.
In all of the above examples, the introduction of a check valve into the filling port of the container would allow emptying of the contents of the container during normal use, and prevent refilling by an unauthorized party. However, the use of a check valve would also prevent the legitimate party to refill the container, thus negating the advantage incurred by its use. It would therefore be advantageous if the check valve could be made bidirectional when desired by an authorized party.
In a case where the container has separate inlet and outlet ports, it would be desirable if the inlet port would contain a tamper-proof valve which could only be actuated by an authorized party.
U.S. Pat. No. 4,390,130 to Linssen discloses an electromagnetically actuatable valve which serves to inject fuel into the intake tube of an internal combustion engine having externally supplied ignition. A movable valve member in the form of a ball element dynamically alternates between two positions depending on the state of a magnetic element.
It is an object of the present invention to provide a valve which is tamper proof and which is externally actuated by an encoded device.
It is a further object of the present invention to provide a check valve which can be made bi-directional.
It is a still further object of the present invention to provide a valve system which is operable only by an authorized party.
It is another object of the present invention to provide a method for preventing the unauthorized filling of a fluid container.
In one aspect of the invention, there is provided a valve for controlling fluid flow therethrough into a container comprising, (1) a valve housing; and (2) a flow control element which, in a first state, prevents fluid flow through the valve housing in a specified direction. The operation of the flow control element is controlled by a dedicated actuator means, wherein the flow control element may be caused to be reversibly altered to a second state by an external control means thereby allowing fluid flow through the valve housing in the specified direction. The external control means operates through the dedicated actuator means, and the dedicated actuator means is sealed within the valve housing or within the container.
In the present specification, the following terms have the indicated meanings:
Fluid includes any flowable material such as e.g. liquids, powders or particles and gases.
Flow control elementxe2x80x94a movable valve element that opens, shuts or partially obstructs an opening in a fluid passageway. Non-limiting examples of such elements are the valve elements of check, gate, globe, needle, plug and butterfly valves.
Actuator meansxe2x80x94a device which causes the flow control element to pass from one state to another. Non-limiting examples of such means are a solenoid, a magnet, a piston, an electromagnet and a motor.
A xe2x80x9cdedicatedxe2x80x9d objectxe2x80x94an object to which operational access is restricted by an encoded device, so that only authorized users who are in possession of the code may access the object. Non-limiting examples of xe2x80x9cdedicationxe2x80x9d devices are a microprocessor, a smart chip, a transponder, infra-red transmission and an encoded magnet.
xe2x80x9csealedxe2x80x9d objectxe2x80x94an object to which physical access is restricted by the structure of the valve housing or container, so that the object cannot be accessed using conventional opening means (such as screws).
External control meansxe2x80x94means outside the valve housing which actuate the actuator means. Non-limiting examples of external control means are a wireless control terminal which activates a magnetic coil by, e.g. radio waves, a wired control terminal, a control terminal which transfers energy to a secondary coil by induction (the primary coil being in the terminal), and an encoded magnet.
The valve of the present invention comes to prevent the filling of a fluid container through a port by an unauthorized party, and, at the same time, comes to allow filling of the container through the same port by an authorized party. The valve of the invention combines two features: (1) the actuator means which controls the operation of the flow control element is dedicated (as defined above); (2) the actuator means is sealed (as defined above) within the valve housing. This combination of features makes the valve tamper-proof and actuatable by authorized parties only.
The valve of the invention differs from conventional valves in that the actuator means is sealed within the valve housing. In most actuated valves having an actuator means, an option exists to manually operate the valve or to service the actuator means by removing or inactivating the actuator means. In the present invention, on the other hand, the actuator means cannot be accessed (other than by physically breaking the valve housing or the container), so that if the actuator means fails, it becomes necessary to replace the entire valve.
The valve of the invention may be mounted within or on the input port of a fluid container, so that only a party possessing the code of the dedicated actuator means may fill the container. Alternatively, the valve may be mounted within the container, proximately to the input port, so that the actuator means is sealed within the container.
Examples of fluid containers which may be used with the valve of the invention include but are not limited to domestic gas cylinders, gas storage tanks, gasoline tanks, tanks or cylinders containing air, oxygen, nitrogen, helium, hydrogen, carbon dioxide, cooling gases such as freon, concentrated soft drinks, beer kegs, etc.
In one embodiment of the first aspect of the invention, there is provided a check valve for controlling fluid flow therethrough, comprising a valve housing and a flow control element. The flow control element in a first state, allows fluid flow through the valve housing in one direction but not in an opposite direction, wherein the flow control element may be caused to be reversibly altered to a second state by a dedicated external control means thereby allowing fluid flow through the valve housing in the opposite direction.
The check valve of the invention in a first state operates as a conventional check valve, but can be reversibly altered to a second state by an external control means, in which it operates as a bidirectional valve. The valve housing may be any conventional housing as is well known to the skilled man of the art. The flow control element may be any standard check valve element such as in a swing, ball or vertical valve.
The flow control element in a first state allows fluid flow in one direction but not in the opposite direction, as in a conventional check valve. The element, however, may be altered to a second state in which the fluid flow is also permitted in the opposite direction, unlike a conventional check valve. The displacement of the control element is effected by a dedicated external control means, so that a functional correlation exists between the control means and the flow control element, as will be described in more detail below. The flow control element may return to the first state either by operation of the control means, or by its removal, depending on its mode of operation.
In a second aspect of the invention, there is provided a valve system for controlling fluid flow comprising:
(a) a valve, comprising a valve housing, and a flow control element which, in a first state, prevents fluid flow through the valve housing in a specified direction, the operation of the flow control element being controlled by a dedicated actuator means; and
(b) an external control means capable of causing the flow control element to be reversibly altered to a second state thereby allowing fluid flow through the valve housing in the specified direction, the external control means operating through the dedicated actuator means,
wherein the dedicated actuator means is sealed within the valve housing.
In one embodiment of the second aspect of the invention, there is provided a valve system for controlling fluid flow comprising a check valve according to the invention and an external control means capable of causing the flow control element of the check valve to be reversibly altered from the first state to the second state.
In a third aspect of the invention, there is provided a device for preventing unauthorized access to the interior of a fluid container comprising a port. The device is mounted on the port, and comprises a check valve according to the invention.
By using the check valve of the invention, unauthorized filling of a fluid container can be prevented, while the authorized party is able to fill the container by using the dedicated control means in his possession. The check valve may be placed either in the cock of the container, or in the container itself.
In a fourth aspect of the invention, there is provided a method for preventing unauthorized filling access to the interior of a fluid container, the container comprising a port, the method comprising the step of sealing the port with a device comprising a valve according to the invention.
In one embodiment of this aspect of the invention, there is provided a method for preventing unauthorized access to the interior of a fluid container, the container comprising a port, the method comprising the step of sealing the port with a device comprising a check valve according to the invention.